Teeth whitening compositions and methods

ABSTRACT

Disclosed herein are teeth whitening compositions generally including an oxidizing agent (e.g., a peroxide), and an activating agent that has an emission wavelength between about 400 nm and about 570 nm (e.g., Eosin B). Methods of employing these compositions to whiten teeth, methods of making these compositions and kits that include some or part of the composition ingredients, are also described.

FIELD OF THE INVENTION

The present invention relates generally to teeth whitening compositions.More specifically, the invention relates to teeth whitening compositionsand kits that can be employed to provide a desired whitening effect(e.g., at least two shades of whitening) in less than 20 minutes (e.g.,in about 1 minute) without significant post-treatment sensitivity.

BACKGROUND OF THE INVENTION

Peroxide and peroxyacid compounds, such as hydrogen peroxide andcarbamide peroxide, have been disclosed as useful in teeth whiteningcompositions. Application of UV or visible light from e.g., Argonlasers, has been employed to accelerate whitening after application ofperoxide compositions to the teeth. Additionally, whitening compositionshave been described that include compounds capable of absorbing lightand converting it to heat or chemical energy, such as the metal-ligandcomplexes and metal chelate precursors described in U.S. Pat. No.6,343,933 to Montgomery et al.

Red dyes have also been employed to absorb visible or UV energy andproduce heat in a bleaching composition as described, e.g., in U.S. Pat.No. 6,485,709 to Banerjee et al. This patent also describes attempts tofurther enhance such compositions by adding metal ions, anorgano-metallic enzyme (e.g., catalase), or using high pH (e.g., above7) to destabilize or activate the decomposition of hydrogen peroxide.Teeth whitening compositions have also been described that includeviolet or blue-violet dyes to counter-stain yellow teeth in U.S. Pat.No. 6,030,222 to Tarver. Rhodamine B dye has been employed in a teethwhitening composition as described in WO 02/22097 to Verheyen et al.

Tooth sensitivity following treatment, and the time required for teethwhitening compositions (typically requiring about an hour of time ormultiple applications or both), however, remains a significant drawback.

SUMMARY OF THE INVENTION

The present invention provides novel compositions and methods thatwhiten teeth in a surprisingly short amount of time (e.g., about 1 to 10minutes) and with minimal or no sensitivity post-treatment. Theinvention is based, in part, on the discovery that the use of the dyesdescribed herein dramatically accelerates the whitening process.

Without wishing to be bound to any particular theory, it is believedthat inclusion of these dyes significantly enhances the compositions ofthe invention at least because it is believed that dentin transmitsgreen light and absorbs blue light. Accordingly, the dyes of the presentinvention enhance whitening not only at the surface of the tooth, butalso may be transmitting light into the tooth to enhance the alterationof color agents by radicals that have penetrated into the tooth surface.

Another advantage of the present invention is that the compositions canbe effective when applied only for a short period of time (e.g., 1minute in some embodiments). Accordingly, sensitivity due to, e.g.,percolation of hydrogen peroxide to the pulp tissue causing (e.g.,pulpal inflammation), may be minimized or eliminated. Another advantageof the present invention is that the compositions do not requirecompounds that generate heat, and therefore, discomfort associated withcompositions that generate heat may be minimized or eliminated. Yetanother advantage is that dyes can be used (e.g., Eosin B) that are lesstoxic than dyes such as Rhodamine B.

In one aspect, the present invention features a tooth whiteningcomposition which includes an oxidizing agent and an activating agenthaving an emission wavelength between about 400 nm and about 570 nm.

In one embodiment, the activating agent is capable of emitting greenlight, blue light or blue-green light, and/or absorbs green light, bluelight or blue-green light. In another embodiment, the activating agentcomprises Eosin B, Erythrosin B, or both.

In another embodiment, the composition further includes a stabilizingagent. In one embodiment, the stabilizing agent is sodium acetate.

In one embodiment, the composition further includes a thickening agent.In one embodiment, the thickening agent is silicon dioxide and/or fumedsilica having a particle size less than one micron.

In one embodiment, the composition further includes a hydrophilicgelling agent. In another embodiment, the composition further includesan accelerator agent. In some embodiments, the accelerator agentincludes sodium perborate.

In one embodiment, the pH of the composition is between about 8 andabout 10.

The invention also features a method for tooth whitening includingapplying the tooth whitening composition of the present invention to atleast one tooth, and exposing the tooth whitening composition to actiniclight such that the tooth is whitened at least about one shade. In oneembodiment, the tooth is whitened at least about two shades in less thanabout 10 minutes or in less that about 5 minutes.

In one embodiment, post-treatment sensitivity is insignificant oreliminated.

In one embodiment, the tooth is exposed to the tooth whiteningcomposition for less than 5 seconds per application.

The invention also features a kit for teeth whitening including a toothwhitening composition of the invention and an apparatus for preparingand/or applying the composition.

The invention also features a kit for tooth whitening including a toothwhitening composition of the invention and instructions for determininga composition application time to achieve a desired whitening effect.

The invention also features a method for tooth whitening including atleast one application of actinic light and a tooth whitening compositionto at least one tooth such that the tooth is whitened at least about twoshades with less than about 1 minute of total exposure to actinic light.In one embodiment, the tooth is whitened at least about three shades inless than about 30 seconds. In another embodiment, there is nosignificant post-treatment sensitivity.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In order to more clearly and concisely describe the subject matter ofthe claims, the following definitions are intended to provide guidanceas to the meaning of specific terms used in the following writtendescription, examples and appended claims.

the term “accelerating agent” refers to any agent capable ofaccelerating and/or contributing to the completion of radical generation(e.g., sodium perborate).

The term “actinic light” refers to light energy capable of beingabsorbed by an activating agent.

The term “activating agent” refers to any agent capable of absorbingactinic light. Preferably, the activating agent enhances and/oraccelerates the dispersion of light energy, or otherwise enhances and/oractivates the decomposition of an oxidizing agent. Activating agentsinclude agents capable of absorbing light energy and emitting lightenergy, e.g., fluorochromes. Suitable activating agents include, e.g.,Eosin B and Erythrosin B.

The term “oxidizing agent” refers to any agent capable of oxidizing, andalso includes precursors of compounds capable of oxidizing. Examples ofoxidizing agents include, but are not limited to, peroxide, peroxy acid,hydrogen peroxide, carbamide peroxide, alkali metal peroxides, alkalimetal percarbonates, peroxyacetic acid, and alkali metal perborates.

The term “post-treatment sensitivity” refers to sensitivity or instantpain experienced by a subject after a tooth whitening procedure.Sensitivity can include, but is not limited to, stimuli such astemperature and pressure. Instant pain typically occurs without stimuli.The terms “significant sensitivity” or “significant post-treatmentsensitivity” and the like, refer to significant discomfortpost-treatment, including sensitivity and/or instant pain for more thanfour hours. The term “insignificant pain” refers to minimum sensitivityto stimuli such as temperature and/or pressure for less than four hourspost-treatment.

The term “stabilizing agent” refers to any agent that stabilizes one ormore agents of the composition (e.g., an oxidizing agent such ashydrogen peroxide). The stabilizing agent can act to stabilize the agentor agents against spontaneous or unwanted reactivity in use and/or instorage. Suitable stabilizing agents include sodium acetate. In someinstances, the stabilizing agent can stabilize hydrogen peroxide forabout one year.

The term “total exposure to actinic light” refers to the total time atooth is exposed to actinic light including multiple applications ofactinic light over the course of a treatment session.

The term “transparent” refers to a composition capable of at least 70%transmission of light. The term “translucent” refers to a compositioncapable of at least about 40% transmission of light. The light referredto can be, e.g., actinic light (e.g., from a laser), emitted light(e.g., from a fluorochrome), or both.

The term “translucency agent” refers to any agent capable of increasingthe translucency of a composition. Such agents can increasetranslucency, e.g., upon addition to the composition, upon activation(e.g., by heat, actinic light and/or emitted light), or both.

When ranges are disclosed herein (e.g., wavelength, pH, concentration,particle sizes, and whitening ranges) all individual values and rangeswithin the disclosed ranges are regarded as part of and encompassed bythe present invention. All concentrations are provided in weight % ofthe composition unless indicated otherwise.

Where “a”, “an” or the like is used herein, these articles are used inthe open or non-restrictive sense, e.g., to indicate “at least one” or“one or more.” Similarly, the term “or” is used in the open ornonrestrictive sense, i.e., to mean “and/or.” Accordingly, the terms“or” and “and/or” are used interchangeably and are meant to have thesame meaning.

In one aspect, the present invention provides tooth whiteningcompositions that include an oxidizing agent (e.g., hydrogen peroxide),and an activating agent that has an emission wavelength between about400 nm and about 570 nm (e.g., Eosin B or Erythrosin B or both). Thecomposition can also include additional agents including, but notlimited to, pH adjusting agents, thickening agents, stabilizing agents,accelerating agents, gelling agents, translucency agents.

The oxidizing agent can be any oxidizing agent known in the art. In oneembodiment, the oxidizing agent includes hydrogen peroxide or sodiumperborate or both. Additionally or alternatively, the oxidizing agentcan include carbamide peroxide, alkali metal peroxides, alkali metalpercarbonates, alkali metal perborates or combinations of thesecompounds. The oxidizing agents can be, e.g., liquid gel, or pastecompositions capable of interacting with the activating compound whenexposed to actinic light.

The concentration of the oxidizing agent can be varied in the presentinvention. In one embodiment, the oxidizing composition includes ahydrogen peroxide, e.g., in a range of about 1% to about 70%. In afurther embodiment, the oxidizing composition includes about 50%hydrogen peroxide.

The activating agent can include any agent with an emission wavelengthbetween about 400 nm and about 570 nm. In another embodiment, theactivating agent emits light in the range of between about 435 nm andabout 520 nm. In one embodiment, the activating agent emits light in therange of between about 520 nm and about 565 nm. In certain embodiments,the agent both absorbs and emits light in the above ranges. In oneembodiment, the activating agent emits green light. In anotherembodiment, the activating agent emits blue-green light. In oneembodiment the activating agent both absorbs and emits green light.

In one embodiment, the activating agent includes Eosin B or ErythrosineB or both. In another embodiment, the whitening composition includes inthe range of about 0.5% to about 0.8% or between about 0.2% and about1.2%, or less than about 12%, of Eosin B. In yet another embodiment, thecomposition includes about 0.2 to about 12% of Eosin B and from about0.01% to about 0.1% or about 0.005% and about 0.15%, of Erythrosine B.Without wishing to be bound to any particular theory it is believed thatthe combination of Eosin B and Erythrosine B has a synergistic effect.It is believed this synergistic effect may be related to the closeabsorption peaks of the dyes. It is further believed that because EosinB and Erythrosine B re-emit green light, that this green light can andmay be further absorbed (or re-absorbed) by the fluorochromes so thatlight energy is not dissipated as in conventional compositions. Thisabsorbed and re-emitted light not only penetrates throughout thebleaching gel, bus also is transmitted into the enamel and dentin. Dyessuch as Eosin B are also advantageous as they are significantly lesstoxic than dyes such as Rhodamine B.

Without wishing to be bound to any particular theory, it is believedthat because dentin and enamel transmit green light, light in this rangecan be transmitted into the dentin and/or enamel of the tooth, causingexcitation of electrons in specific chemical bonds within the activatingagent and tooth chromaphores, making them more susceptible to beattacked by free radicals. The activating agents of the invention caninclude blue-green and/or blue emitting dyes. Accordingly, the presentinvention is based, at least in part, on the discovery that the use ofthe activating agents of the invention significantly enhance and/orcontribute to the enhancement of a whitening effect in a fraction of thetime required by conventional compositions. Because the teeth are onlyexposed to the whitening composition for a fraction of the time ascompared to conventional teeth whitening compositions, superficialcracks and crevices, caused by prolonged exposure to free radicals, canbe reduced or eliminated. Because decalcification can occur in thecracks and crevices caused by prolonged exposure to free radicals,stains more easily return as the decalcified enamel acts as a sponge. Inthe present invention, the decreased exposure time to free radicalsreduces the possibility of crevices and cracks, thus leading to asignificantly prolonged or permanent whitening effect for deeperpigments. Moreover, prolonged periods of exposure cause the enamel tobecome brittle. It is believed that the composition and methods of thepresent invention avoid compromise of the enamel.

In one embodiment, the activating agent or agents not only are capableof emitting light in the wavelength range from about 400 nm to about 570nm, but also absorb light in the wavelength range from about 400 nm toabout 570 nm. Such an activating agent is activated by light in thewavelength range of from about 400 nm to about 570 nm. Accordingly, inone embodiment the activating agent absorbs light in the wavelengthrange of about 400 nm to about 570 nm. In another embodiment, theactivating agent absorbs light at a wavelength between about 470 nm toabout 550 nm. This embodiment therefore allows for the optimalabsorption of energy from the actinic light and the optimal transmissionthrough dentin and enamel.

Without wishing to be bound to any particular theory, it is alsobelieved that activating agents of the present invention, when exposedto actinic light, can accelerate the dispersion of light energy whichconsequently leads to an instantaneous and complete photochemicalactivation of the peroxide within the gel. It is believed that the gelmass better transmits light in the wavelength range of about 400 nm toabout 570 nm, so that when an activating agent is exposed to actiniclight, the dispersion of the light energy leads to an acceleratedphotochemical activation of the peroxide. Together, these embodimentsallow for optimal absorption by the activating agent of energy from theactinic light and the optimal transmission through the composition,dentin and enamel.

In one embodiment, the composition also includes a stabilizing agent. Inone embodiment, the stabilizing agent stabilizes the peroxideconcentration in the composition for days, weeks, months, a year orseveral years. In one embodiment, the stabilizing agent not onlystabilizes the oxidizing agent, but also is a pH modifier and/orstabilizer. In another embodiment, the stabilizing agent is sodiumacetate. In one embodiment, sodium acetate is added until the desired pHis attained. In yet another embodiment, the composition includes betweenabout 0.1% and about 50% stabilizing agent. Any value or range withinthis range is meant to be encompassed.

In one embodiment, the stabilizing agent is selected from the groupconsisting of antioxidants such as sodium sulfite, metal chelators(e.g., EDTA), and stabilizers (e.g., tin salts, phosphoric acid, and tinsulphonates). In some embodiments, the stabilizing agent scavenges orotherwise isolates or removed from solution, metal ions that canpotentially destabilize the hydrogen peroxide.

In one embodiment, the stabilizing agent is or includes sodium acetate(e.g., sodium acetate trihydrate). Sodium acetate has been found toinhibit spontaneous reactivity of hydrogen peroxide and therefore canprovide improved stability.

In one embodiment, the pH of the composition is in or adjusted to therange of from about 4 to about 10. In alkaline conditions, with a pHfrom about 8 to about 10, the stronger free radical, perhydroxyl ions,can be generated. Perhydroxyl free radicals are capable of reacting notonly with yellow and brown stains but even with grey chromophoressituated deeper in the tooth structure. In further embodiments, the pHof the composition is between about 5 and about 7, or between about 5and about 6. In certain embodiments the pH is about 6.

Suitable pH adjusting agents include, but are not limited to, sodiumhydroxide, potassium hydroxide, ammonium hydroxide, sodium carbonate,potassium carbonate, TRIS, and triethanolamine, or any other salt of analkaline base which is safely used in the mouth. In another embodiment,the pH adjusting agent is sodium perborate. In certain embodiments ofthe invention, a single component may act as a pH adjusting agent or asa stabilizing agent or may serve both functions. In one embodiment,sodium acetate acts as a pH adjusting agent and as a stabilizing agent.In further embodiments, the pH adjusting agent is of the groupconsisting of sodium bicarbonate, calcium bicarbonate, sodium carbonateand calcium carbonate.

Additionally or alternatively, the composition can include a thickeningagent to improve the ease of application of the composition to the teethsuch that even and effective coverage is more readily achieved. Suitablethickening agents include but are not limited to mixed silica-aluminumoxides, long chain hydrocarbons such as synthetic carbomers (e.g.,Carbopol), triethanolamine (e.g., Trolamine), and water soluble poly(ethylene oxide) resins (e.g., Polyox). Suitable thickening agents alsoinclude amide starches.

It has been found that using an agent which has a particle size in therange from about 0.2 microns (μm) to about 0.7 μm provides for morewidespread dispersion of the oxidizing agent on the particle surface.Accordingly, in one embodiment, the activating agent has a particle sizebelow about 2 microns or below about 1 micron. In other embodiments, theagent has a particle size below about 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, or0.2 microns. In other embodiments, the activating agent has a particlesize between about 0.1 and about 0.8, between about 0.2 and about 0.7,or between about 0.3 and about 0.6 microns.

Additionally or alternatively, the thickening agent can include fumedsilica and/or any other inert inorganic material that may be used as acarrier and can aid in the delivery of active oxygen to the toothsurface. Fumed silica of a small particle size (e.g., between about 0.2microns and about 0.4 microns), can provide efficient dispersion ofhydrogen peroxide and reflection of light energy within the oxidizingcomposition.

In some embodiments, the compositions of the invention include areaction accelerator or accelerating agent. In one embodiment, thecomposition includes sodium perborate. Sodium perborate has selectivereactivity with hydrogen peroxide in forming free radicals (reacts withwater to release hydrogen peroxide). The use of one or more activatingagents (e.g., sodium perborate) can be advantageous because they canabsorb and retain heat generated in the composition by, e.g., actiniclight, thus restricting any such heat to the gel in order to acceleratethe reaction without heating the tooth, which can cause sensitivity. Inaddition, acceleration of the reaction means that the composition can beremoved more quickly than conventional compositions thereby decreasingexposure of the patient to the composition and resulting sensitivityand/or other damage to tissues and teeth.

In one embodiment, the compositions of the invention include betweenabout 0.8% and about 15%, or between about 0.3% and about 18%accelerator agent.

In further embodiments, the compositions of the invention include agelling agent. Preferably the gelling agent is also a translucencyagent. For example, a hydrophilic gelling agent can be employed toincrease the translucency of the resulting composition or gel.

In some embodiments, the nature of the gelling agent (e.g., itshydrophilic nature) prevents vaporization of the gel when exposed toactinic light, thus improving hydration of the coated tooth area.Increased hydration of the teeth and surrounding tissues is associatedwith decreased discomfort and sensitivity. In one embodiment, thegelling agent can include, for example, one or more modified starchesand/or glucose. In one embodiment, modified starches and/or glucose areactivated in cold water. In some embodiments, the gelling agent furtherenhances the consistency of the composition, facilitating theapplication to the tooth surface.

The translucency agent can enhance translucency or transparency uponaddition to the composition and/or upon activation by, e.g., actiniclight, emitted light and/or heat. In one embodiment, it minimizesvaporization of the composition. Additionally or alternatively, thegelling and/or translucency agent minimizes any thermal effects byabsorbing any heat generated in the composition.

In one embodiment the composition is a translucent composition. Inanother embodiment the composition is a transparent composition. Incertain embodiments, the composition is translucent or transparent tothe actinic light it will be exposed to (e.g., green, blue-green or bluelight).

In one embodiment, the composition includes an oxidizing agent (e.g.,hydrogen peroxide), an accelerating agent (e.g., sodium perborate), anactivating agent (Eosin B or Erythrosin B or both), a stabilizing agent(e.g., sodium acetate trihydrate), a pH adjusting agent, a thickeningagent (e.g., fumed silica or silicon dioxide or both), and a gellingagent. In one embodiment, the pH of the composition is from about 6 toabout 10. In some embodiments, the pH of the composition is from about 8to about 10.

Another aspect of the invention provides a method for tooth whiteningincluding applying a tooth whitening composition of the presentinvention to at least one tooth, and exposing the tooth whiteningcomposition to actinic light to activate the oxidizing agent. Thecomposition may be any of the compositions described herein.

In one embodiment, the method for bleaching the teeth is performed in adentist's office or dental operatory under ordinary conditions. Thecomposition can be mixed chair-side and applied to the surfaces of asmany teeth as are desired to be whitened. Alternatively, the compositioncan be provided without the need for mixing chair-side. Thereafter, thecomposition can be exposed to actinic light to accelerate decompositionof the oxidizing agent and the formation of free radicals. In oneembodiment, premixes can be prepared with some or all of the ingredientsand then mixed chairside and applied to the teeth. In one embodiment, ahydrogen peroxide/sodium acetate solution premix can be prepared andstored prior to use. Additionally or alternatively, some or all of theremaining ingredients can also be separately premixed and stored priorto use. Such premises can be stored, e.g., for at least about one year.

The compositions of the invention can be used to whiten teeth discoloredby any agent or disorder. For example, the compositions may be used towhiten discoloration due to stains (e.g., tobacco, coffee, tea and/orfood stains), fluorosis, developmental disturbances, bacteria, genetics,tetracycline antibiotics, trauma, blood decomposition, pigments presentduring development of teeth, etc.

Any source of actinic light can be used and preferably it is capable ofemitting light in a wavelength appropriate to the activating agentemployed in the composition. In one embodiment, e.g., an argon laser isused. In another embodiment, a potassium-titanyl phosphate (KTP) laser(e.g., a GreenLight™ laser) is used as a light source. In one embodimentthe light source emits light at or near the absorption wavelength of theactivating agent or at least one of the activating agents, if severalare included in the composition.

The most intense fluorescence (e.g., emission) from a fluorochrome dyeoccurs when it is irradiated with wavelengths close to the peak of theabsorption wavelength (i.e., excitation curve). Accordingly, in oneembodiment, the actinic light is at a wavelength of about the absorptionwavelength of the activating agent. In one embodiment, the actinic lighthas a wavelength in the range from about 470 nm to about 550 nm. Inanother embodiment, the actinic light has a wavelength in the range fromabout 470 nm to about 520 nm. In yet another embodiment, an argon laserprovides actinic light in the wavelength range from about 470 nm toabout 520 nm. In a further embodiment, the actinic light has awavelength of about 530 nm to about 535 nm. In still another embodiment,the source of actinic light in the wavelength range of about 530 nm toabout 535 nm is a KTP laser. In this embodiment the source is a KTPlaser set at about 532 nm. In another embodiment, a photocuring deviceis the source of actinic light.

In one embodiment, the tooth is exposed to actinic light for less than20 minutes, in another for less than 10 minutes, in another for lessthan 5 minutes. In one embodiment the tooth is exposed to actinic lightfor less than 4, 3, 2, or 1 minute. In one embodiment, the inventionprovides a method for whitening teeth at least 2 shades in about 1minute. In some embodiments, there is no significant post-treatmentsensitivity. In other embodiments, there is no post-treatmentsensitivity.

In one embodiment, the tooth whitening composition is applied and thetooth is exposed to multiple applications of actinic light, for a timeof about 4 to about 6 seconds each tooth per exposure. In someembodiments, the tooth is exposed to actinic light at least two, three,four, five or six times. In some embodiments, a fresh application of thetooth whitening composition is applied before each exposure to actiniclight. In some embodiments, the total exposure to actinic light is lessthan about one minute. In other embodiments, the total exposure toactinic light is less than about 60, 40, 30, or 20 seconds.

In one embodiment, the tooth is whitened at least 7 shades, 6 shades, 5shades, 4 shades, 3 shades, 2 shades or 1 shade. Shades can bedetermined before and after treatment using any of a number of shadeguides, including, e.g., the VITA® (Vita Zahnfabrik H. Rauter GmbH &Co., KG), CHROMASCOP® (Ivoclar Vivadent, Inc.) or BIODENT (DentsplyInternational) shade guides. Optionally, a shade taking system, e.g.,the ShadeEye NCC Dental Chroma Meter, can be employed to determine shadebefore and/or after treatment.

In one embodiment, the tooth is whitened at least two shades, threeshades, four shades, five shades, six shades or seven shades in lessthan about one minute of total exposure time to actinic light. In someembodiments, the tooth is whitened at least two shades, three shades,four shades, five shades, six shades or seven shades in less than about40 seconds of total exposure time to actinic light. In some embodiments,the tooth is whitened at least two shades, three shades, four shades,five shades, six shades or seven shades in less than about 30 seconds oftotal exposure time to actinic light. In some embodiments, the tooth iswhitened at least two shades, three shades, four shades, five shades,six shades or seven shades in less than about 20 seconds or even lessthan about 10 seconds of total exposure time to actinic light.

In one embodiment, the risk of transient inflammation of the pulp bypercolation of hydrogen peroxide is reduced, not significant and/oreliminated. Without wishing to be bound by any particular theory,inflammation of the pulp is thought to be caused by percolation ofhydrogen peroxide into the pulp tissue. In some embodiments, thesynergistic effect of the activating agents (e.g., Eosin B andErythrosin B), and the actinic light results in an instantaneous andcomplete photochemical reaction. Accordingly, exposure of the tooth, thepulp, and/or the surrounding tissues to the oxidizing agent and/or othercomponents in the composition is dramatically reduced.

In yet another aspect, the invention provides a method for toothwhitening comprising application of actinic light and a composition ofthe invention (any of the compositions described herein) to at least onetooth such that the tooth is whitened at least about two shades in lessthan about 10 minutes. In another embodiment, the tooth is whitened atleast about two shades in less than about 5 minutes, less than about 4minutes, less than about 3 minutes, less than about 2 minutes or inabout 1 minute. In some embodiments, the teeth are whitened at leastabout 3 shades, 4 shade or 5 shades. In some embodiments, there is nosignificant post-treatment sensitivity or no post-treatment sensitivity.

In yet another aspect, the invention provides a kit for preparing orapplying a tooth whitening composition in accordance with the presentinvention. In one embodiment, the kit includes an oxidizing agent and anactivating agent that has an emission wavelength between about 400 nmand about 570 nm. The composition can be any of the compositions of thepresent invention. In one embodiment, the composition is not combined,and may optionally include apparatus to combine two or more componentsor premixes of the composition. In another embodiment the compositiondoes not require any combination (i.e., it is ready to use and does notrequire any pre-mixing chair-side).

In another embodiment, the kit includes a composition of the inventionand directions for application. Additionally or alternatively, the kitcan include apparatus for application (e.g., brushes or trays or both).The kit can also include charts or other information helpful inassessing the whitening effect desired and/or achieved by the methodsand compositions of the invention. The kit can also include a source ofactinic light.

Identification of equivalent compositions, methods and kits are wellwithin the skill of the ordinary practitioner and would require no morethan routine experimentation, in light of the teachings of the presentdisclosure. Practice of the invention will be still more fullyunderstood from the following examples, which are presented herein forillustration only and should not be construed as limiting the inventionin any way.

Example 1: Preparation of an Exemplary Whitening Composition andActivation by Actinic Light

A premix was prepared by mixing 4 mg of Eosin B, 1 mg Erythrosine B, 450mg fumed silica, and 45 mg sodium perborate. Separately, the pH of a 50%hydrogen peroxide solution was adjusted to pH 6 using sodium acetatesolution. Approximately 4-6 ml of the adjusted hydrogen peroxidesolution was then added to the premix in a plastic mixing chamber andimmediately applied.

The gel was applied to frontal surface of the teeth of each subjectbeginning from the frontal anterior incisors, followed by theposteriors, and finally the posterior incisors. The gel was activated bya KTP laser set at a continuous wave of 0.5 watts. The laser was appliedto each tooth for 2-3 seconds. During this time, the gel turned fromorange-red to transparent and eventually became dull. After 3-4 minutesfor two full arches from premolar to premolar, the gel was aspirated,and the teeth were lightly scrubbed with a cotton roll to clean thesurface of the enamel. A second coating of gel was applied using freshgel and activated with the KTP laser as described above. Up to sixconsecutive applications were performed to achieve the desired whiteningeffect for each patient. The duration of the sessions typically did notexceed 40 minutes.

Comparative Example 2: Whitening Effect of Composition

A comparative study was conducted on 10 volunteers between an exemplarycomposition of the present invention and the SMARTBLEACH laser teethwhitening systems, which is a composition comprising Rhodamine B andhydrogen peroxide. The shade of each patient's teeth was recorded priorto application of whitening composition.

Teeth were coated with the composition prepared in Example 1 and exposedto actinic light from a green laser set at 532 nm for one minute for theentire mouth (4-5 seconds per tooth) and then the composition wasremoved. The comparative composition was applied to the teeth andexposed to light from a green laser set at 532 nm for 30 seconds pertooth and then left on the surface of the tooth for 10 minutes, inaccordance with the manufacturer instructions provided with thecomposition. The comparative composition required at least 3 to 4applications, for a total duration of about 1.5 hours for the entiremouth. The composition was removed from each volunteer and the teethwere irrigated with water. The teeth were then evaluated using the VITAscale for the whitening effect of the compositions. Patients were alsoevaluated for any post-treatment sensitivity by asking them to rate thelevel of pain experience if any.

The Smartbleach™ treatment resulted in a shade change of one to twoshades in the yellow group, while the exemplary composition of thepresent invention resulted in a shade change of 5 shades in the yellowgroup, e.g., A₄ to B₁ VITA scale. In the “yellow group” (A₄-A₁),treatment with the exemplary composition of the present inventionresulted in shade changes of 4-5 shades, resulting in shades in the“white group” (B₁-B₂). Treatment with the exemplary composition forteeth in the “grey” (C₄-C₁) and “grey-brown” (D₄-D₂) groups showedchanges of 2-3 shades in the first session.

The following evaluation scale of post-sensitivity was used:

Level 0 No sensitivity to thermal stimuli or any kind of pain followingtreatment. Level 1 Sensitivity to thermal stimuli that lasts for a fewseconds. Level 2 Pain or discomfort that occurs due to thermal stimuliand lasts for more than one minute. Optional pain treatment withanalgesics. Level 3 Pain or discomfort that occurs automatically,requiring use of analgesics to control the pain.

Following treatment with the Smartbleach™ system, all ten subjectsexperienced pain from Level 1 to Level 3. Following treatment with theexemplary composition of the present invention, nine subjectsexperienced no pain (e.g., Level 0), and only one subject experiencedpain of Level 1.

Comparative Example 3: Effect of Actinic Light Source

A study was conducted on 28 volunteers comparing the effect of differentactinic light sources in whitening with the composition of Example 1. Aprophylactic session was performed on each patient 3-4 days before thebleaching session. The shade of each patient's teeth was recorded priorto application of whitening composition.

Teeth were coated with the composition prepared in Example 1 and exposedto different sources of actinic light: a green laser (KTP) at 532 nm, ablue (argon) laser at 480-414 nm, a photocuring halogen lamp, and a LEDphotocuring device.

The activation was performed in the different patients for the left orthe right sides of their dental arches according to an activationrandomization mode. Specifically, a first patient's right side wasactivated with the 532 nm green laser, while the left side was activatedwith the 480 nm-514 nm blue-green laser. A second patient's right sidewas activated with the photocuring halogen lamp, while the left side wasactivated with the LED photocuring device. A third patient's right sidewas activated with the 532 nm green laser, while the left side wasactivated with the photocuring halogen lamp. A fourth patient's rightside was activated with the 532 nm green laser, while the left side wasactivated with the LED photocuring device. A fifth patient's right sidewas activated with the 480 nm-514 nm blue-green laser, while the leftside was activated with the photocuring halogen lamp. A sixth patient'sright side was activated with the 480 nm-514 nm blue-green laser, whilethe left side was activated with the LED photocuring device.

The composition was removed from the teeth of each volunteer and theteeth were irrigated with water. The teeth were then evaluated using theVITA scale for the whitening effect of the compositions.

Activation by different photocuring devices produced comparable results.The speed of activation with the green laser and the blue-green laserwas 4-5 seconds per tooth, while the speed of activation with thephotocuring devices was about 10 seconds per tooth. Accordingly, awhitening session employing the green laser or the blue-green laser forthe entire mouth would typically take approximately 30 minutes, and asession with a photocuring device would typically take approximately 40minutes.

1. A composition comprising: an oxidizing agent; and an activating agenthaving an emission wavelength between about 400 nm and 570 nm, whereinthe activating agent comprises Erythrosine B.
 2. The composition ofclaim 1, wherein the activating agent capable of emitting green light,blue light or blue-green light, and/or absorbs green light, blue lightor blue-green light.
 3. The composition of claim 1, wherein theactivating agent further comprises Eosin B.
 4. The composition accordingto claim 1, wherein the composition comprises a stabilizing agent. 5.The composition according to claim 4, wherein the stabilizing agent issodium acetate.
 6. The composition according to claim 1, wherein thecomposition comprises a thickening agent.
 7. The composition accordingclaim 6, wherein thickening agent is silicon dioxide and/or fumed silicahaving a particle size less than one micron.
 8. The compositionaccording to claim 1, wherein the composition comprises a hydrophilicgelling agent.
 9. The composition according to claim 1, wherein thecomposition comprises an accelerator agent.
 10. The compositionaccording to claim 9, wherein the accelerator agent includes sodiumperborate.
 11. The composition according to claim 1, wherein the pH ofthe composition is between about 8 and about
 10. 12.-20. (canceled) 21.The composition according to claim 1, wherein the oxidizing agent ispresent in the composition in an amount ranging from about 1% to about70%.
 22. The composition according to claim 1, wherein the Erythrosine Bis present in the composition in an amount ranging from about 0.005% andabout 0.15%.
 23. The composition according to claim 3, wherein the EosinB is present in the composition in an amount that is less than about12%.
 24. The composition according to claim 1, further comprising acarbomer.